"Don't be afraid to make some people angry. Boldness pays off. Think of this - in America, you can have 50% of the country dislike you and still be elected president." ~ Dan Kennedy
I can't affirm that 50% stat is 100% accurate, but the point is dead on. When you draw a line in the sand and make clear exactly who your product or service is for - and who it ISN'T for - you immediately set yourself far above the competition. One way to do this is to make very clear in your marketing materials - most specifically the headline - exactly who your product or service is for.
By doing so, this immediately tells the folks you aren't targeting that there's no need to bother with it and thereby skip it and go away. Most advertisers are unwilling to do this because they FEAR turning away anybody, they are indiscriminate, they value quantity above everything else, or they have failed to actually design a business that is "for" anybody in particular.
That's EXACTLY the wrong approach. Unless you have unlimited resources, you simply can't market to every single person on the planet - it just isn't feasible. So you HAVE to discriminate... and by doing so, you send a clear message to your target customer that you recognize their unique needs and desires, and therefore could very well offer premium value to them.